A known sheet supply apparatus is detachably attached to an image forming apparatus configured to form an image on a sheet. The sheet supply apparatus is configured to obtain a drive force from the image forming apparatus to supply a sheet to the image forming apparatus.
The sheet supply apparatus includes a first transmission mechanism and a second transmission mechanism. The first transmission mechanism is configured to transmit the drive force from the image forming apparatus to a sheet supply roller. The second transmission mechanism is configured to transmit the drive force from the image forming apparatus to another sheet supply apparatus.